I got one of these at a Goodwill for 8 bucks which was never opened, and this is a good way to test most Nerf style guns. One word of caution is that if you use it with ball ammo guns (i.e. Nerf Rival), put the target in a deep box because this keeps the ball from ricocheting all over the place.
I got one of these for my son of Amazon for 12 dollars brand new. Really good deal! not sure if you figured, you were shooting the targets too close. Too much power was causing them to stand back up.